Azure-functions-core-tools: JSON serialization differences locally and on Azure for Functions v3

[nzthiago]

That code when run locally (from VS, or VS Code using latest npm based func v3 core tools) behave differently from when deployed to Azure.

Run locally and you get: (the highlighted property names have not been mapped)

PS C:\> (Invoke-WebRequest -Uri http://localhost:7071/api/f1).Content
{"**identifier**":"a3c9ae75-52d7-40db-af92-58be363c61b5","**itemName**":"Item1","**description**":"This is the first item."}

Run in Azure and you get: (which is what I expect)

PS C:\> (Invoke-WebRequest -Uri https://askew.azurewebsites.net/api/f1).Content
{"id":"a3c9ae75-52d7-40db-af92-58be363c61b5","name":"Item1","desc":"This is the first item."}

Locally I tested with core tools version 3.0.2009, and dotnet version 3.1.101. I noticed that locally the runtime was still 3.0.12930. On Azure I deployed to West US, and the host runtime is already 3.0.13107. Not sure if this runtime difference is the cause.

Here's more information:
Function code:

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;

namespace FunctionSerialisation
{
    public static class Function1
    {
        [FunctionName("Function1")]
        public static Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = "f1")] HttpRequest req, ILogger log)
        {
            var queryParams = req.GetQueryParameterDictionary();

            var model = new MyModel
            {
                Identifier = Guid.NewGuid().ToString(),
                ItemName = "Item1",
                Description = "This is the first item."
            };

            var ss = new JsonSerializerSettings
            {
                Formatting = Formatting.Indented
            };
            // This compiles but fails at runtime (locally and in Azure)
            //return Task.FromResult<IActionResult>(new JsonResult(model, ss));
            return Task.FromResult<IActionResult>(new JsonResult(model));
        }
    }
}

CSProj:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <AzureFunctionsVersion>v3</AzureFunctionsVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Mvc.Formatters.Json" Version="2.2.0" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions" Version="3.0.5" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.Http" Version="3.0.2" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Host.Storage" Version="3.0.14" />
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="3.0.2" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
</Project>

Model class:

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Text;
using System.Text.Json.Serialization;

namespace FunctionSerialisation
{
    public class MyModel
    {
        [JsonProperty("id"), JsonPropertyName("id")]
        public string Identifier { get; set; }

        [JsonProperty("name"), JsonPropertyName("name")]
        public string ItemName { get; set; }

        [JsonProperty("desc"), JsonPropertyName("desc")]
        public string Description { get; set; }

    }
}

[fabiocav]

Assigning for validation. Need to test this against the latest version of Core Tools (matching the Azure Hosted version) and investigate impact.

[fabiocav]

Moving this to sprint 70 as the release is still in progress.

[mhoeger]

Hey @nzthiago - Sorry for the delay! I just checked locally with the following:

Azure Functions Core Tools (3.0.2245 Commit hash: 1d094e2f3ef79b9a478a1621ea7ec3f93ac1910d)
Function Runtime Version: 3.0.13139.0
dotnet version: 3.1.100

And got

PS C:\Users\mahoeger> (Invoke-WebRequest -Uri http://localhost:7071/api/f1).Content
{"id":"25a4aa6f-f22b-4cb4-aecc-19f3ae02b36b","name":"Item1","desc":"This is the first item."}

I ran it back with core tools 3.0.2009 and did see the incorrect response as well. Closing as resolved with latest!